The train carrying iron from Zouerate to the coast at Nouadhibou, is probably the world's longest train. Normally its length is as much as 3 kilometres. The whole journey takes around 12 hours, where almost 700 kilometres are covered. If you want to come to, or leave, Nouadhibou, there are no good alternatives to this train. But it should not be avoided anyway.Nowadays, normal compartments have been put up. Up until a few years ago, sitting on top of the wagons, was all offered. This is still used, but it's unpleasant. The cost of travelling is just around $5 one way (1 ougiya per kilometre.)